Method for a chemical and/or electrolytic surface treatment of a substrate in a process station

ABSTRACT

The invention relates to a method for a chemical and/or electrolytic surface treatment of a substrate in a process station and a process station for a chemical and/or electrolytic surface treatment of a substrate. 
     The method for a chemical and/or electrolytic surface treatment comprises the following steps, not necessarily in this order:
         mounting a substrate to be treated to a rotor unit,   moving the rotor unit with the substrate into a pre-wetting chamber of the process station,   applying a pre-wetting fluid to the substrate in the pre-wetting chamber,   moving the rotor unit with the substrate at least partially out of the pre-wetting chamber,   spinning the rotor unit with the substrate in a spinning plane to centrifugally reduce the pre-wetting fluid at a surface of the substrate,   rotating the rotor unit with the substrate normal to the spinning plane so that the substrate faces away from the pre-wetting chamber,   moving the rotor unit with the substrate into an electroplating chamber of the process station,   applying an electrolyte liquid and an electric current to the substrate for an electroplating process on the substrate in the electroplating chamber, and   moving the rotor unit with the substrate at least partially out of the electroplating chamber.

TECHNICAL FIELD

The invention relates to a method for a chemical and/or electrolyticsurface treatment of a substrate in a process station and a processstation for a chemical and/or electrolytic surface treatment of asubstrate.

BACKGROUND

In the microelectronics industry, there are several processes wheresmall recesses on substrates have to be filled with a conductive metal(e.g. Cu), which is usually performed through so-called electroplating,electrochemical deposition, electrochemical plating or galvanicdeposition. In specific cases, especially when very small and deeprecesses have to be filled with a conductive material, such processesare sometimes also called high aspect ratio plating.

During the process of electrochemical deposition very often difficultiesarise, because the recesses are filled with surrounding ambient air, inwhich the substrates are stored, handled or processed before the actualplating process. When the substrates containing the small recesses areimmersed into the liquid electrolyte, the ambient air inside a smallrecess can form a gaseous barrier. The gaseous barrier then prevents theelectrolyte to wet and penetrate into the recess and by doing so blocksor at least significantly deteriorates the deposition process forfilling of the recess with an uninterrupted conductive material layer. Adiscontinuous or even interrupted coating or filling of the recess leadsto e.g. voids within the material layer, loose contacts or eveninterrupted electrical circuits. In addition, the reliability,functionality and life span of a device with such non-adequate plated orfilled recesses is commonly reduced.

Conventionally, ambient air is removed before and sometimes also duringan electroplating process from such small recesses by means ofsub-atmospheric pressure or vacuum in a pressure-controlled chamber. Thesubsequent plating or filling of the recesses has then to be donewithout interrupting the sub-atmospheric pressure or vacuum, which isvery cumbersome, expensive and poses many issues and technologychallenges to be implemented in a high volume and high throughputmanufacturing process in order for the deposition process to deliver aqualified result.

When the plating is directly followed by the pre-wetting step underreduced pressure without release of the reduced pressure back toatmospheric pressure, the applicability to high volume manufacturing islimited. The limitation is based on the complexity of the toolconstruction, the costs involved to build and maintain the equipment, aswell as the electrochemical processing challenges introduced whenprocessing has to happen under reduced pressure. Further, the platingchamber needs to be capable to withstand certain levels of vacuum(pressure regulatable chambers and systems).

In another implementation, a prior rinsing of the recesses under variouspressure conditions with an inert or degassed pre-wetting liquid can beperformed on the substrates in a separate pre-wetting chamber before thesubstrate is transferred into a plating chamber where the recesses willbe filled through electrochemical deposition. However, this is a verytime consuming and complex procedure involving significant wet-substratehandling challenges from the pre-wet chamber to the plating chamber.This procedure is also cost intensive, as additional chambers have to bededicated to just the pre-wet process, which in addition adds to theoverall footprint of the tool, blocking very expensive manufacturing andcleanroom space.

A corresponding pre-wetting apparatus method and design is disclosed inUS 2015/179458 A1: The method of electroplating a layer of copper on awafer substrate comprises (a) providing the wafer substrate having anexposed metal layer on at least a portion of its surface to apre-wetting process chamber; (b) contacting the wafer substrate with apre-wetting fluid under sub-atmospheric pressure, the pre-wetting fluidcomprising water and copper ions, to form a layer of pre-wetting fluidon the wafer substrate; (c) contacting the pre-wetted wafer substratewith a plating solution, the plating solution comprising copper ions, toelectroplate a layer of copper on the wafer substrate, wherein theconcentration of copper ions in the pre-wetting fluid is greater thanthe concentration of copper ions in the plating solution.

In case a separate pre-wetting chamber is applied, a disadvantage can befound in the large build size of the system (due to the additionalchamber requirements), which means the tool requires a significantlylarger manufacturing and/or cleanroom space. Another disadvantage is theneed to transfer wet substrates from one chamber to the other withoutlosing the liquid filling inside the recesses by full or only partialdrying and without tripping liquid all over the tool space, which cancause lifetime and contamination issues with the tool.

SUMMARY

Hence, there may be a need to provide an improved method for a chemicaland/or electrolytic surface treatment of a substrate in a processstation, which is in particular easier than conventional methods.

The problem is solved by the subject-matters of the independent claimsof the present invention, wherein further embodiments are incorporatedin the dependent claims. It should be noted that the aspects of theinvention described in the following apply also to a method for achemical and/or electrolytic surface treatment of a substrate in aprocess station and a process station for a chemical and/or electrolyticsurface treatment of a substrate.

According to the present invention, a method for a chemical and/orelectrolytic surface treatment of a substrate in a process station ispresented. The method for a chemical and/or electrolytic surfacetreatment comprises the following steps, not necessarily in this order:

-   -   mounting a substrate to be treated to a rotor unit,    -   moving the rotor unit with the substrate into a pre-wetting        chamber of the process station,    -   applying a pre-wetting fluid to the substrate in the pre-wetting        chamber,    -   moving the rotor unit with the substrate at least partially out        of the pre-wetting chamber,    -   spinning the rotor unit with the substrate in a spinning plane        to centrifugally reduce the pre-wetting fluid at a surface of        the substrate,    -   rotating the rotor unit with the substrate normal to the        spinning plane so that the substrate faces away from the        pre-wetting chamber,    -   moving the rotor unit with the substrate in an electroplating        chamber of the process station,    -   applying an electrolyte liquid and an electric current to the        substrate for an electroplating process on the substrate in the        electroplating chamber, and    -   moving the rotor unit with the substrate at least partially out        of the electroplating chamber.

The present method for a chemical and/or electrolytic surface treatmentof a substrate in a process station makes the surface treatment of thesubstrate in a process station significantly better manageable. Itcomprises a pre-wetting step in the process station, which can be doneprior to a subsequent electroplating step in the process station withoutrequiring an elaborate wet handling of the pre-wetted substrate from thepre-wetting chamber to the electroplating chamber. As a result, thepresent method allows reducing significantly process complexity andcosts, because no involved wet substrate handling is necessary. There isno tripping liquid all over the tool space, which can cause lifetime andcontamination issues. Further, the present method allows reducing anoverall equipment size and manufacturing cleanroom footprintrequirements.

The substrate may comprise a conductor plate, a semi-conductorsubstrate, a film substrate, an essentially plate-shaped, metal ormetallized workpiece and/or the like. The substrate may be held in asubstrate holder.

The rotor unit can be understood as a device configured to rotate thesubstrate. It may comprise a drive unit and a holding unit for thesubstrate. The drive unit may be an engine with a transmission. Thedrive unit may be connected to the holding unit by means of an arm. Theholding unit may be a frame to hold the substrate. The rotor unit can beused as a substrate holding and supporting device for a combinedpre-wetting and electroplating process. The rotor unit may support asupply of a pre-wetting pressure (e.g. vacuum) and/or a pre-wettingatmosphere (e.g. a gas different to air) and/or an electrical current(e.g. up to 100 Ampere and more for the electroplating process) to thesubstrate. The rotor unit may enable a lateral movement of the substrate(e.g. up and down) and/or a spin movement (e.g. horizontally in or alonga substrate surface and around an approximate center of the substrate)and/or a rotational movement around an axis normal to the spin movementof the substrate (e.g. tilt the substrate upwards to downwards). Thisallows process configurations for the substrate to be rotated e.g. fromfront-side-up on top of the rotor unit to front-side-down below therotor unit.

The pre-wetting fluid can be understood as a liquid providing thefunction of pre-wetting the substrate. It can be water, high puritywater and/or the like.

The pre-wetting chamber can be understood as a space or housing, inwhich the pre-wetting of the substrate may take place. After thepre-wetting, the substrate may be partially or completely moved out ofthe pre-wetting chamber. The movement direction out of the pre-wettingchamber may be a first movement direction. The substrate may then bearranged below the pre-wetting chamber.

The spinning plane can be understood as the plane in which the substrateis spun. The spinning plane may be normal to an imaginary connectionline between the pre-wetting chamber and the electroplating chamber. Thespinning plane may be parallel to the substrate surface or the spinningplane may correspond to an extension of the substrate surface.

The wording “centrifugally reduce the pre-wetting fluid” can beunderstood in that the pre-wetting fluid is removed from a surface ofthe substrate, but still remains in recesses of the substrate.

Accordingly, in the step of spinning, the rotor unit holding thesubstrate may revolve around a center of the substrate or the spinningplane. In other words, the rotor unit may spin horizontally relative tothe substrate surface or the spinning plane to remove the pre-wettingfluid from the surface of the substrate.

When the rotor unit and the substrate is rotated normal to the spinningplane, this can be understood in that the substrate is tilted. Beforerotating, the substrate faces the pre-wetting chamber, which can beunderstood to be directed upwards. After rotating, the substrate facesthe electroplating chamber, which can be understood to be directeddownwards.

The wording “normal to the spinning plane” can be understood as“perpendicular to the spinning plane” or “vertical to the spinningplane”. Further, the wording “normal to the imaginary connection line”may be understood as “perpendicular to the imaginary connection line” or“vertical to the imaginary connection line”.

Accordingly, to move the substrate from the pre-wetting chamber to theelectroplating chamber of the process station, the rotor unit holdingthe substrate may pivot vertically by 180° such that the rotor unit maybe still arranged perpendicular to the spinning plane but it may bedirected towards an opposite side before rotating.

The electrolyte liquid can be understood as a liquid providing thefunction of an electrolyte.

The electroplating process may be an electroplating, an electrochemicaldeposition, an electrochemical plating, a galvanic deposition and/or thelike.

The electroplating chamber can be understood as a space or housing, inwhich the electroplating process may take place. After theelectroplating, the substrate may be partially or completely moved outof the electroplating chamber. The movement direction out of theelectroplating chamber may be a second movement direction, which isdifferent and in particular opposite to the first movement direction.The substrate may then be arranged above the electroplating chamber.

The present method for a chemical and/or electrolytic surface treatmentof a substrate can be understood to take place in the same processstation. This means the pre-wetting chamber and the electroplatingchamber are arranged in the same process station. In other words, theentire method for a chemical and/or electrolytic surface treatment of asubstrate is done in the same process station. The substrate does notleave the process station during and between pre-wetting andelectroplating. The process station comprises the pre-wetting chamber,the rotor unit and the electroplating chamber. The substrate may befixed to the rotor unit and may then be moved by the rotor unit into thepre-wetting chamber, out of the pre-wetting chamber, to theelectroplating chamber, into the electroplating chamber and out of theelectroplating chamber. This can be done without releasing the substratefrom the rotor unit and in particular without changing the fixture ofthe substrate to the rotor unit. As a result, a build size or footprintof a system for chemical and/or electrolytic surface treatment of asubstrate can be rather small and a method for a chemical and/orelectrolytic surface treatment can be done rather fast. In particular, aqueue time and/or a transfer time can be rather limited, becausesubsequent steps of the method can be done immediately after one anotherand nearly without any transfer.

In an embodiment, the method for a chemical and/or electrolytic surfacetreatment comprises the step of

-   -   modifying a gas system in the pre-wetting chamber before the        pre-wetting step.

The modification of the gas system can be a reduction of pressurerelative to atmospheric pressure before the pre-wetting step. Thereduction of pressure can be followed by an increase of pressure toatmospheric pressure after the pre-wetting step. Alternatively oradditionally, the modification of the gas system can be an exchange ofgas relative to ambient air before and/or after the pre-wetting step.Generally, vacuum, reduced pressure relative to ambient pressure,ambient pressure and/or increased pressure relative to ambient pressuremay be applied to the substrate in the pre-wetting chamber. Ambient airor another gas may be applied to the substrate in the pre-wettingchamber. In particular, a soluble gas like e.g. CO₂ may be applied tothe substrate prior to the subsequent electroplating. There is no needto maintain the modification of the gas system (e.g. vacuum) after thepre-wetting and during the electroplating. Without such requirement, theplating chamber and plating process is easier, leading to furtherreduced process complexity as well as further reduced overall equipmentsize and manufacturing cleanroom footprint requirements.

The step of mounting a substrate to be treated to a rotor unit can beunderstood in that the substrate is loaded onto the rotor unit, which isenabled to support the substrate for the entire following process steps(from pre-wetting to electroplating to optionally rinsing and/ordrying). For example, the substrate is mounted to the rotor unit througha clamping action of an electrical contact ring, which is closed afterthe substrate is loaded onto the rotor unit. The electrical clampingring allows that a substrate front side and/or the complete substratecan be electrically connected and polarized, which means converted intoa cathode during the electroplating process). Alternatively or inaddition, the substrate is mounted to the rotor unit through vacuumsuction forces or magnetic forces or the like.

The step of moving the rotor unit with the substrate in a pre-wettingchamber of the process station can be understood in that the rotor unitholding the substrate is moved in an e.g. upper part of the processstation and into the pre-wetting chamber. A sealing between thepre-wetting chamber and the rotor unit can be established. A remainingopen volume between the rotor unit and an interior of the pre-wettingchamber is thereby made very small so that only a small volume needs tobe evacuated or flooded with an alternative gaseous medium. Theevacuation or flooding can then be done extremely fast and/or with avery low consumption of flushing gas. Once the sealing between thepre-wetting chamber and the rotor unit is achieved, the pre-wetting assuch or a combined pressure reduction and pre-wetting follows.

The step of applying a pre-wetting fluid to the substrate in thepre-wetting chamber allows removing gaseous barriers of ambient airwhich in particular fill recesses of the substrate. The term “recess”can be understood as an open cavity with a diameter in a range ofmillimeters, micrometers or nanometers. When the substrate is immersedinto the liquid electrolyte, the ambient air inside the recesses canform a gaseous barrier, which prevents the electrolyte to wet andpenetrate into the recess and by doing so blocks or deteriorates thedeposition process for covering and filling the substrate and itsrecesses with an uninterrupted deposition material layer.

The step of applying a pre-wetting fluid to the substrate can beunderstood in that before the application of the pre-wetting liquid,optionally, a reduced pressure (e.g. 0.7 bar) may be applied to thesubstrate to remove ambient air out of recesses of the substrate to alevel, which is not negatively impacting the process results anymore.This means gaseous barriers inside the recesses are reduced so that thefollowing pre-wetting fluid can penetrate and wet bottom and sidewallsof the recesses. As soon as the gaseous barriers are sufficientlyreduced (e.g. based on prior experimental determination of theduration), the pre-wetting fluid can be dispensed onto the substratesurface to penetrate all recesses and replace ambient air inclusionsinside the recesses. The step of pre-wetting can also comprise only theapplication of the pre-wetting liquid without a prior subjection toreduced pressure.

After all recesses are sufficiently pre-wetted (e.g. based on priorexperimental determination of the duration), the reduced pressure orvacuum can be released to achieve atmospheric ambient pressure (about 1bar). This can be achieved by means of a gas stream into the open volumebetween the rotor unit and the interior of the pre-wetting chamber. Thegas stream may be air, nitrogen, gases soluble in the pre-wetting liquid(e.g. CO₂ or SO₂) or the like.

The step of moving the rotor unit with the substrate at least partiallyout of the pre-wetting chamber can be understood in that the rotor unitwith the substrate is moved into a spin position (e.g. 25 mm below thepre-wetting position).

The step of spinning the rotor unit with the substrate in a spinningplane to centrifugally reduce the pre-wetting fluid at a surface of thesubstrate can be understood as a spinoff of an excess of the pre-wettingfluid through a spinning of the rotor unit at e.g. several hundred rpm.

The step of rotating the rotor unit with the substrate normal to thespinning plane so that the substrate faces away from the pre-wettingchamber can be understood in that the rotor unit with the substrateundergoes a rotational movement around an axis normal to the rotationalspin movement of the substrate. The rotor unit with the substrate isthen in a position to face e.g. down towards the electroplating chamber.

The step of moving the rotor unit with the substrate into anelectroplating chamber of the process station can be understood in thatthe rotor unit holding the substrate is moved to the electroplatingchamber of the processing station, establishes an alignment between theelectroplating chamber and the rotor unit, and enters the electroplatingchamber.

The step of applying an electrolyte liquid and an electric current tothe substrate for an electroplating process on the substrate in theelectroplating chamber can be understood in that the electroplatingprocess is started. For the electrochemical process, the electroplatingchamber of the process station contains an anode (in a state of oppositeelectrical polarization to the substrate), which is required to performan electrochemical deposition of e.g. Cu or any other material that canbe electrochemically deposited onto the substrate and into the recesses.An electroplating chamber also contains an electrolyte in which thesubstrate is submersed at the time the electrochemical process isstarted. The electrochemical process can be carried out in various waysfrom a slow, steady state plating to very high-speed plating. The rotorunit may supply up to 100 Ampere and more of current. In an embodiment,the electroplating is done in ambient air. In an embodiment, theelectroplating is done in atmospheric pressure.

The step of moving the rotor unit with the substrate at least partiallyout of the electroplating chamber can be understood in that, when theelectrochemical deposition process is determined as finished, the rotorunit is removed from the electroplating chamber.

In an embodiment, the method for a chemical and/or electrolytic surfacetreatment further comprises the following steps after moving the rotorunit with the substrate out of the electroplating chamber:

-   -   rotating the rotor unit with the substrate so that the substrate        faces towards the pre-wetting chamber,    -   moving the rotor unit with the substrate in the pre-wetting        chamber, and    -   applying a rinsing liquid to the substrate in the pre-wetting        chamber to remove the electrolyte liquid from the substrate.

This can be understood in that the rotor unit is removed from theelectroplating chamber and rotated back into its initial position. Thesubstrate may then be e.g. on top of the rotor unit and might be movedin the pre-wetting chamber again. The wording “in the chamber” can beunderstood as at least partially or completely into the chamber. Inother words, “in the chamber” can be understood as next to or in theproximity of the chamber or as completely into an interior of thechamber. The wording “in the proximity of the pre-wetting chamber” canbe understood as in a spin off position. In the pre-wetting chamber, arinsing liquid may be dispensed onto the substrate surface to remove anyelectrolyte residues from the surface. As a summary, the rinsing canhappen inside the pre-wetting chamber, but can also happen in theproximity of the pre-wetting chamber.

In an embodiment, the method for a chemical and/or electrolytic surfacetreatment further comprises the step:

-   -   applying a drying flow to the substrate in the pre-wetting        chamber to dry the substrate.

This can be understood in that the substrate undergoes a drying processin the pre-wetting chamber in order to enable a dry handling of thesubstrate from the rotor unit to e.g. a substrate transportation systemor to a subsequent processing step for which the rotor unit moves into asubstrate loading/unloading position. Again, the wording “in thepre-wetting chamber” can be understood as in the proximity of thechamber or as partially into the interior of the chamber or ascompletely into the interior of the chamber. Preferably, drying is donein the proximity to the pre-wetting chamber in the spin off position.

According to the present invention, also a process station for achemical and/or electrolytic surface treatment of a substrate ispresented. The process station comprises:

-   -   a rotor unit,    -   a pre-wetting chamber, and    -   an electroplating chamber,

The rotor unit is configured to hold the substrate to be treated and tomove the substrate at least partially into and out of the pre-wettingchamber and into and out of the electroplating chamber.

The pre-wetting chamber is configured to pre-wet the substrate by meansof a pre-wetting fluid with or without the application of a reducedatmosphere.

The electroplating chamber is configured to apply an electrolyte liquidand an electric current to the substrate for an electroplating processon the substrate.

The rotor unit is further configured to spin the substrate in a spinningplane and to rotate with the substrate normal to the spinning plane sothat the substrate faces towards the pre-wetting chamber or towards theelectroplating chamber.

The present process station for a chemical and/or electrolytic surfacetreatment of a substrate in a process station makes the surfacetreatment of the substrate in a process station significantlymanageable. The process station comprises the pre-wetting chamber andthe electroplating chamber so that pre-wetting and electroplating can bedone in the process station without requiring an elaborate wet handlingof the pre-wetted substrate from the pre-wetting chamber to theelectroplating chamber. There is no tripping liquid, which can causelifetime and contamination issues. The process station reduces systemcomplexity, size and cost.

The rotor unit may enable a lateral movement of the substrate (e.g. upand down) and/or a spin movement (e.g. horizontally in or along asubstrate surface and approximately around a center of the substrate)and/or a rotational movement around an axis normal to the spin movementof the substrate (e.g. tilt the substrate upwards to downwards).

In an embodiment, the pre-wetting chamber and/or the electroplatingchamber are arranged opposite to each other with the rotor unit inbetween. In an example, one of the chambers is arranged in a firstposition, e.g. on the floor, and the other chamber is arrangedvertically above the first position in a second position. This means,the chambers can be stacked with the rotor unit in between moving thesubstrate vertically between the chambers. In another example, bothchambers are arranged on the floor next to each other with the rotorunit in between moving the substrate horizontally between the chambers.In an embodiment, the process station comprises at least one morechamber.

In an embodiment, the rotor unit comprises a fixing means to fix thesubstrate to the rotor unit. The fixing means can be configured toenable a surface treatment of one or more substrate surfaces. In anembodiment, the fixing means is a clamping element, a magnetic elementand/or a suction element. The suction element can be configured to fixthe substrate by reduced pressure or vacuum.

In an embodiment, the rotor unit comprises a sealing means to close withthe pre-wetting chamber liquid tight and/or gas tight. In an embodiment,the rotor unit comprises a sealing means to close with theelectroplating chamber liquid tight and/or gas tight.

In an embodiment, the rotor unit comprises a gas supply system to supplygas to the pre-wetting chamber. The gas may be used for providing aspecific atmosphere for the pre-wetting and/or for drying the substrate.The drying can be done in the electroplating chamber, in the pre-wettingchamber and/or between and outside these chambers.

In an embodiment, the rotor unit comprises a pressure reduction systemto reduce a pressure in the pre-wetting chamber. In particular, therotor unit may comprise two vacuum application elements, one for holdingthe substrate and one for reducing the pressure in the pre-wettingchamber.

In an embodiment, the rotor unit is configured to spin the substratewith 1500 rounds per minute and more, preferably 2000 rounds per minute.

In an embodiment, the rotor unit comprises an electric energy supplysystem to provide an electric current to the substrate for theelectroplating process in the electroplating chamber. Preferably, theelectric current amounts to 50 Ampere and more, more preferably 100Ampere and more.

In an embodiment, the rotor unit comprises a rinsing liquid supplysystem to supply a rinsing liquid to the substrate.

It shall be understood that the method and the device according to theindependent claims have similar and/or identical preferred embodiments,in particular, as defined in the dependent claims. It shall beunderstood further that a preferred embodiment of the invention can alsobe any combination of the dependent claims with the respectiveindependent claim.

These and other aspects of the present invention will become apparentfrom and be elucidated with reference to the embodiments describedhereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary embodiments of the invention will be described in thefollowing with reference to the accompanying drawing:

FIG. 1 shows schematically and exemplarily an embodiment of a processstation for a chemical and/or electrolytic surface treatment of asubstrate according to the invention.

FIG. 2 shows schematically and exemplarily the process station for achemical and/or electrolytic surface treatment of a substrate accordingto FIG. 1 in another position.

FIG. 3 shows schematically and exemplarily the process station for achemical and/or electrolytic surface treatment in another position.

FIG. 4 shows schematically and exemplarily the process station for achemical and/or electrolytic surface treatment in still anotherposition.

FIG. 5 shows schematically and exemplarily the process station for achemical and/or electrolytic surface treatment in still anotherposition.

DETAILED DESCRIPTION OF EMBODIMENTS

FIG. 1 shows schematically and exemplarily a process station 10 for achemical and/or electrolytic surface treatment of a substrate 20. Theprocess station 10 comprises a pre-wetting chamber 12, an electroplatingchamber 13, and a rotor unit 11. The pre-wetting chamber 12 and theelectroplating chamber 13 are arranged opposite to each other with therotor unit 11 in between.

The pre-wetting chamber 12 is a housing, in which a pre-wetting andoptionally a rinsing and/or a drying of the substrate 20 takes place.The electroplating chamber 13 is a housing, in which an electroplatingprocess takes place. The pre-wetting chamber 12 and the electroplatingchamber 13 are arranged in the same process station 10. The substrate 20does not leave the process station 10 during and between pre-wetting andelectroplating.

As explained in more detail further below with reference to the otherFigures, the rotor unit 11 moves the substrate 20 into the pre-wettingchamber 12, out of the pre-wetting chamber 12, to the electroplatingchamber 13, into the electroplating chamber 13 and out of theelectroplating chamber 13, back to the pre-wetting chamber 12, and outof the pre-wetting chamber 12. This is done without releasing thesubstrate 20 from the rotor unit 11 and in particular without changingthe fixture of the substrate 20 to the rotor unit 11.

The rotor unit 11 therefore comprises a drive unit 111 and a holdingunit 112 for the substrate 20. The drive unit 111 is an engine with atransmission. The holding unit 112 is a frame element to hold thesubstrate 20.

The rotor unit 11 holds the substrate 20 and provides a supply of apre-wetting pressure (e.g. vacuum) and/or a pre-wetting atmosphere (e.g.a gas different to air) and/or an electrical current (e.g. up to 100Ampere and more for the electroplating) to the substrate 20. The rotorunit 11 therefore comprises a pressure supply system 113, a gas supplysystem 114 and an electric energy supply system 115. The rotor unit 11further comprises a rinsing liquid supply system to supply a rinsingliquid to the substrate 20.

The rotor unit 11 enables a lateral movement of the substrate 20 (up anddown) and/or a spin movement (horizontally in a substrate 20 surface andapproximately around a center of the substrate 20) and/or a rotationalmovement around an axis normal to the spin movement of the substrate 20(tilt the substrate 20 upwards to downwards). This allows the substrate20 to be moved up and down, be centrifuged and to be rotated fromfront-side-up on top of the rotor unit 11 to front-side-down below therotor unit 11 as shown in the following:

A method for a chemical and/or electrolytic surface treatment of asubstrate 20 in a process station 10 comprises the following steps, notnecessarily in this order and not necessarily all of them:

-   S1. mounting a substrate 20 to be treated to a rotor unit 11 (see    FIG. 1 ),-   S2. moving the rotor unit 11 with the substrate 20 into a    pre-wetting chamber 12 of the process station 10 (see FIG. 2 ),-   S3. optionally modifying a gas system in the pre-wetting chamber 12    (see FIG. 2 ),-   S4. applying a pre-wetting fluid to the substrate 20 in the    pre-wetting chamber 12 (see FIG. 2 ),-   S5. optionally modifying the gas system in the pre-wetting chamber    12 (see FIG. 2 ),-   S6. moving the rotor unit 11 with the substrate 20 at least    partially out of the pre-wetting chamber 12 (see FIG. 3 ),-   S7. spinning the rotor unit 11 with the substrate 20 in a spinning    plane to centrifugally reduce the pre-wetting fluid at a surface of    the substrate 20 (see FIG. 3 ),-   S8. rotating the rotor unit 11 with the substrate 20 normal to the    spinning plane so that the substrate 20 faces away from the    pre-wetting chamber 12 (see FIG. 4 ),-   S9. moving the rotor unit 11 with the substrate 20 into an    electroplating chamber 13 of the process station 10 (see FIG. 4 ),-   S10. applying an electrolyte liquid and an electric current to the    substrate 20 for an electroplating process on the substrate 20 in    the electroplating chamber 13 (see FIG. 4 ),-   S11. moving the rotor unit 11 with the substrate 20 out of the    electroplating chamber 13 (see FIG. 5 ),-   S12. optionally rotating the rotor unit 11 with the substrate 20 so    that the substrate 20 faces towards the pre-wetting chamber 12 (see    FIG. 5 ),-   S13. optionally moving the rotor unit 11 with the substrate 20 into    or into proximity of the pre-wetting chamber 12 (see FIG. 5 ),-   S14. optionally applying a rinsing liquid to the substrate 20 inside    or in proximity of the pre-wetting chamber 12 (see FIG. 5 ), and-   S15. optionally applying a drying flow to the substrate 20 in the    pre-wetting chamber 12 (see FIG. 5 ).

As shown in FIG. 1 , the step S1 of mounting the substrate 20 to therotor unit 11 means that the substrate 20 is loaded onto the rotor unit11, which supports, holds and moves the substrate 20 for the entirefollowing process steps (from pre-wetting to electroplating tooptionally rinsing and/or drying).

As shown in FIG. 2 , the step S2 of moving the rotor unit 11 with thesubstrate 20 into the pre-wetting chamber 12 of the process station 10means that the rotor unit 11 with the substrate 20 is moved upwards intoan upper part of the process station 10 and into the pre-wetting chamber12. A sealing is established between the pre-wetting chamber 12 and therotor unit 11.

Step S3 of modifying a gas system in the pre-wetting chamber 12 is areduction of pressure (e.g. 0.7 bar or vacuum) relative to atmosphericpressure before the pre-wetting step to e.g. remove ambient air out ofrecesses of the substrate 20. The modification of the gas system canalso or additionally be an exchange of gas in contrast to ambient air.

Step S4 of applying a pre-wetting fluid to the substrate 20 in thepre-wetting chamber 12 means that the pre-wetting fluid penetrates andwets the substrate 20 and in particular bottoms and sidewalls ofrecesses in the substrate 20.

Step S5 of modifying the gas system in the pre-wetting chamber 12 is anincrease of the pressure after step S3 back to atmospheric pressure. Thereduced pressure or vacuum of step S3 is released to achieve atmosphericambient pressure (about 1 bar). This is achieved by means of a gasstream out of the rotor unit 11 or through a gas supply system installedon the chamber into an open volume between the rotor unit 11 and theinterior of the pre-wetting chamber 12. The gas stream may be air,nitrogen, gases soluble in the pre-wetting liquid (e.g. CO2 or SO2) orthe like. The modification of the gas system can also or additionally bean exchange of gas back to ambient air. There is no need to maintain anymodification different to ambient air and pressure after thepre-wetting.

As shown in FIG. 3 , the step S6 of moving the rotor unit 11 with thesubstrate 20 out of the pre-wetting chamber 12 can be understood in thatthe rotor unit 11 with the substrate 20 is moved into a spin position(e.g. 25 mm) below the pre-wetting position and below the pre-wettingchamber 12.

Step S7 of spinning the rotor unit 11 with the substrate 20 in aspinning plane S to centrifugally reduce the pre-wetting fluid at asurface of the substrate 20 can be understood as ejecting an excess ofthe pre-wetting fluid through the spinning of the rotor unit 11 and thesubstrate 20 at e.g. several hundred rpm. The wording “centrifugallyreduce the pre-wetting fluid” means that the pre-wetting fluid isremoved from a surface of the substrate 20, but still remains inrecesses of the substrate 20. The spinning plane S can be understood asthe plane in which the substrate 20 is spun. The spinning plane isnormal to an imaginary connection line between the pre-wetting chamber12 and the electroplating chamber 13. The spinning plane S may beparallel to a surface of the substrate 20 or an extension of the surfaceof the substrate 20. The rotor unit 11 can spin the substrate 20 withe.g. 1500 rounds per minute or 2000 rounds per minute around a center ofthe substrate 20.

As shown in FIG. 4 , the step S8 of rotating the rotor unit 11 with thesubstrate 20 normal to the spinning plane means that the substrate 20 istilted and now faces away from the pre-wetting chamber 12. The rotorunit 11 with the substrate 20 is subjected to a rotational movementaround an axis normal to the rotational spin movement of the substrate20 as shown in FIG. 3 . The rotor unit 11 with the substrate 20 is nowin a position to face down towards the electroplating chamber 13. Inother words, the rotor unit 11 pivots by 180° in a vertical directionsuch that the rotor unit 11 and the substrate 20 can be directed to theelectroplating chamber 13.

Step S9 of moving the rotor unit 11 with the substrate 20 in theelectroplating chamber 13 of the process station 10 can be understood inthat the rotor unit 11 holding the substrate 20 is moved to theelectroplating chamber 13 of the processing station, establishes analignment between the electroplating chamber 13 and the rotor unit 11,and then enters the electroplating chamber 13.

Step S10 of applying an electrolyte liquid and an electric current tothe substrate 20 for the electroplating process of the substrate 20 inthe electroplating chamber 13 means that the electroplating processtakes places. The rotor unit 11 may supply up to 100 Ampere and more ofcurrent. The electroplating can be done in ambient air and/or atatmospheric pressure.

As shown in FIG. 5 , the step S11 of moving the rotor unit 11 with thesubstrate 20 out of the electroplating chamber 13 can be understood inthat the rotor unit 11 is removed from the electroplating chamber 13.The substrate 20 is then above the electroplating chamber 13.

Step S12 of rotating the rotor unit 11 with the substrate 20 means thatthe substrate 20 now faces again towards the pre-wetting chamber 12. Thesubstrate 20 is on top of the rotor unit 11.

Step S13 is moving the rotor unit 11 with the substrate 20 back into orin proximity to the pre-wetting chamber 12.

Step S14 is applying a rinsing liquid to the substrate 20 in thepre-wetting chamber 12 to remove electrolyte residues from the substrate20.

Step S15 is applying a drying flow to the substrate 20 inside thepre-wetting chamber 12 or in close proximity to dry the substrate 20.The substrate 20 is subjected to a dry process in the pre-wettingchamber 12 in order to enable a dry handling of the substrate 20 fromthe rotor unit 11 to e.g. a substrate 20 transportation system.

It has to be noted that embodiments of the invention are described withreference to different subject matters. In particular, some embodimentsare described with reference to method type claims whereas otherembodiments are described with reference to the device type claims.However, a person skilled in the art will gather from the above and thefollowing description that, unless otherwise notified, in addition toany combination of features belonging to one type of subject matter alsoany combination between features relating to different subject mattersis considered to be disclosed with this application. However, allfeatures can be combined providing synergetic effects that are more thanthe simple summation of the features.

While the invention has been illustrated and described in detail in thedrawings and foregoing description, such illustration and descriptionare to be considered illustrative or exemplary and not restrictive. Theinvention is not limited to the disclosed embodiments. Other variationsto the disclosed embodiments can be understood and effected by thoseskilled in the art in practicing a claimed invention, from a study ofthe drawings, the disclosure, and the dependent claims.

In the claims, the word “comprising” does not exclude other elements orsteps, and the indefinite article “a” or “an” does not exclude aplurality. A single processor or other unit may fulfil the functions ofseveral items re-cited in the claims. The mere fact that certainmeasures are re-cited in mutually different dependent claims does notindicate that a combination of these measures cannot be used toadvantage. Any reference signs in the claims should not be construed aslimiting the scope.

1. A method for a chemical and/or electrolytic surface treatment of asubstrate in a process station, comprising: mounting a substrate to betreated to a rotor unit, moving the rotor unit with the substrate into apre-wetting chamber of the process station, applying a pre-wetting fluidto the substrate inside the pre-wetting chamber, moving the rotor unitwith the substrate at least partially out of the pre-wetting chamber,spinning the rotor unit with the substrate in a spinning plane tocentrifugally reduce the pre-wetting fluid at a surface of thesubstrate, rotating the rotor unit with the substrate normal to thespinning plane so that the substrate faces away from the pre-wettingchamber, moving the rotor unit with the substrate into an electroplatingchamber of the process station, applying an electrolyte liquid and anelectric current to the substrate for an electroplating process on thesubstrate inside the electroplating chamber, and moving the rotor unitwith the substrate at least partially out of the electroplating chamber.2. The method according to claim 1, wherein the pre-wetting chamber andthe electroplating chamber are arranged in the same process station. 3.The method according to claim 1, further comprising the step ofmodifying a gas system in the pre-wetting chamber, wherein themodification of the gas system is a reduction of pressure relative toatmospheric pressure before the pre-wetting step, an increase ofpressure to atmospheric pressure after the pre-wetting step and/or anexchange of gas relative to ambient air before and/or after thepre-wetting step.
 4. The method according to claim 1, wherein theelectroplating is done in ambient air and/or atmospheric pressure. 5.The method according to claim 1, further comprising the following stepsafter moving the rotor unit with the substrate out of the electroplatingchamber: rotating the rotor unit with the substrate so that thesubstrate faces towards the pre-wetting chamber, moving the rotor unitwith the substrate into the pre-wetting chamber, and applying a rinsingliquid to the substrate in the pre-wetting chamber to remove theelectrolyte liquid from the substrate.
 6. The method according to claim1, further comprising the step: applying a drying flow to the substratein the pre-wetting chamber to dry the substrate.
 7. A process stationfor a chemical and/or electrolytic surface treatment of a substrate,comprising a rotor unit, a pre-wetting chamber, and an electroplatingchamber, wherein the rotor unit is configured to hold a substrate to betreated and to move the substrate at least partially in and out of thepre-wetting chamber and in and out of the electroplating chamber,wherein the pre-wetting chamber is configured to pre-wet the substrateby means of a pre-wetting fluid, wherein the electroplating chamber isconfigured to apply an electrolyte liquid and an electric current to thesubstrate for an electroplating process on the substrate, and whereinthe rotor unit is further configured to spin the substrate in a spinningplane and to rotate with the substrate normal to the spinning plane sothat the substrate faces towards the pre-wetting chamber or towards theelectroplating chamber.
 8. The process station according to claim 7,wherein the pre-wetting chamber and/or the electroplating chamber arearranged opposite to each other with the rotor unit in between.
 9. Theprocess station according to claim 7, wherein the rotor unit comprises afixing means to fix the substrate to the rotor unit, wherein the fixingmeans is configured to enable a surface treatment of one or moresubstrate surfaces.
 10. The process station according to claim 7,wherein the rotor unit comprises a sealing means to close thepre-wetting chamber and/or the electroplating chamber liquid tightand/or gas tight.
 11. The process station according to claim 7, whereinthe rotor unit comprises a gas supply system to supply gas to thepre-wetting chamber.
 12. The process station according to claim 7,wherein the rotor unit comprises a pressure reduction system to reduce apressure in the pre-wetting chamber.
 13. The process station accordingto claim 7, wherein the rotor unit is configured to spin the substratewith 1500 rounds per minute and more, preferably 2000 rounds per minute.14. The process station according to claim 7, wherein the rotor unitcomprises an electric energy supply system to provide an electriccurrent to the substrate for the electroplating process in theelectroplating chamber, preferably wherein the electric current amountsto 50 Ampere and larger, more preferably 100 Ampere and larger.
 15. Theprocess station according to claim 7, wherein the rotor unit comprises arinsing liquid supply system to supply a rinsing liquid to thesubstrate.